A technology for reducing power consumption of a display is an important technology in, particularly, a long period of use of battery-powered mobile equipment such as a smartphone and a tablet terminal. As a technology for reducing power consumption of a liquid crystal display (LCD), there is a technology of making luminance of a backlight as low as possible by making a value obtained through integration of a luminance value and luminance of the backlight approach to an observation value (see, for example, Patent Literature 1). However, this technology cannot be applied to a self-luminous display such as an organic light-emitting diode (OLED) display.
As a technology for reducing power consumption of a self-luminous display, there is a technology of reducing luminance by uniformly multiplying luminance of an image by a gain less than 1, or a technology of reducing luminance of a region having predetermined characteristics (see, for example, Patent Literature 2).
However, with the technology of reducing luminance by uniformly multiplying luminance of an image by a gain less than 1, an image wholly becomes dark. Further, with the technology of reducing luminance of a region having predetermined characteristics, because a reduction amount of luminance cannot be finely controlled, image quality degrades.
Further, although there is a technology of controlling a tone curve as a technology for reducing power consumption of a self-luminous display, contrast of the whole screen becomes too high.